New windows have been ordered, and the subject of ventilation has, until now, only been met with the sentence “Then just open them more often.” Before placing the order it is worth having a more concrete discussion: how should the air exchange work in everyday use after the change, and who will consider this question professionally? It is about a planned solution, not about assigning blame after installation.
Why the question belongs with the order
The Umweltbundesamt describes the connection between tighter construction, reduced unintentional air exchange and the need for active window ventilation or suitable ventilation systems. Its brochure deals with different concepts for residential buildings. [LUFT] From this no specific system or general ventilation rhythm for your flat can be derived here.
Our editorial recommendation: Give the technical discussion its own field “Air exchange after window replacement”. Do not let it disappear between the product colour and the delivery date. The selection of the windows and the assessment of the whole building are different tasks whose interaction should be clarified.
Describe everyday use without diagnosing yourself
Outline which rooms are used how and when people are typically present. Note existing ventilation facilities and known peculiarities, without deducing their cause from a photo. If previous examinations or recommendations exist, submit them with the date. Unknown wall constructions and untested installations should remain recognisable as open information.
Ask the specialist to assess this starting point and to name any necessary next steps. A brief statement after a mere glance at the window list should not be treated in your files as a comprehensive building assessment.
An example of a better request for a quote
In a fictional flat everyone is out of the house during the day. A quote mentions only the replacement of the elements. The owner therefore asks: Who assesses how the necessary air exchange is to be secured under our usage conditions? Which planning or investigation is included, and which must be commissioned separately?
That is more helpful than immediately ordering a specific device. The answer may initially include an additional planning step. Record whether this should take place before the final product selection and what information the company needs for it.
Securing the handover after installation
Request a clear handover of the operating and maintenance information relevant to the specific solution. Agree to whom questions after commissioning should be directed. Document unusual observations factually and have them assessed, rather than carrying out technical interventions yourself.
This article is not a diagnosis of mould or moisture damage. It also does not assert any blanket legal trigger after a certain number of windows have been replaced. It helps you to include a planning question — often dealt with too late — in the actual order in good time.